Figure 4

Phosphomimetic mutations have a minor effect on the dNTPase activity of SAMHD1 in contrast to the Y146S/Y154S tetramerization-defective mutant.
(A) dNTPase activity as a function of GTP concentration measured for bacterially-expressed SAMHD1115-626 HD domain constructs. (B) dNTPase activity as a function of GTP concentration measured for full-length SAMHD1 constructs expressed in mammalian cells.